This project aims to contribute to understanding of the biochemistry of insects, with especial emphasis on hormone action in development and metabolic regulation. In the forthcoming period, we plan to concentrate on analysis of the action of juvenile hormone in inducing the synthesis of vitellogenin (yolk protein precursor) in fat body tissue of the migratory locust and possibly other species. Hormone receptor proteins will be sought, and changes in nucleic acids, including messenger RNA, examined. As an approach to genetic analysis of regulation of vitellogenin synthesis, we shall attempt to map the genes involved in Drosophila by means of segmental aneuploids. A second area of investigation, the enzymic regulation of carbohydrate metabolism, will include study of the glycogen phosphorylase system of insect fat body and the control of direction of carbon from glycogenolysis into products such as trehalose and glycerol. Possible roles of cyclic nucleotides will be examined.